DNS Server
OK so here's what you do:
turn on your Nintendo Wii, go to the Wii Options (bottom-left corner), Wii Settings, Move over to page 2 (Wii System Settings 2), click on: Internet -> Connection Settings -> <choose the connection that's setup for your Wii> -> Change Settings -> Auto-Obtain DNS (a few pages over). Select "No" -> Advanced Setting. Type in the following numbers:
Primary DNS
208.67.222.222
Secondary DNS
208.67.220.220
Confirm, save and do a Wii system update (optional)
Here's the source of my info: How to speed up your Wii's connection wi...
All of these settings can be undone if there are any complications and I urge you to read though the source thread if you have any concerns.